1. Field of the Invention
This invention relates to an improved concrete building block and walls, including retaining walls, built from a plurality of such building blocks. More particularly, the invention relates to interlocking concrete building blocks for forming walls, including retaining walls and insulated building walls.
2. Description of the Prior Art
Conventional eight inch by sixteen inch partially hollow concrete blocks have been used for many years to form walls and support structures. Such blocks are customarily secured together with mortar between the blocks, plus essentially the weight of the blocks which holds one row or course of blocks upon another. However, under severe loads such as in relatively elevated structures, and where there is exposure to shearing forces, such construction, unless reinforced in some manner, usually by being tied to a second parallel wall or structure of some form, is liable to collapse. Interlocking masonry or concrete blocks have been employed to lock together two parallel ceramic walls, but have not been too satisfactory due to excessive cost and weight, and such blocks must be made to rather precise tolerances in order to effectively interlock. In addition, such interlocking blocks have typically required additional grout or mortar as an adhesive or bonding medium.
Various methods for providing insulation in concrete walls have also been used in the past. These include pouring insulation within hollow blocks, placing insulation between two rows of blocks, placing layered insulation between thin layers of ceramic material interlocked into the overall form of a ceramic block, and the like. The use of insulating material incorporated directly into the ceramic material of a block has also been suggested, for example, in the present inventor's own U.S. Pat. No. 4,780,433 which discloses the incorporation into the concrete mix for a ceramic or concrete block of a light, ceramic aggregate derived from garbage and clay material. Such incorporation forms a lightweight, highly insulative block.
There have also been so-called garden blocks, or retaining wall blocks, in which a retaining wall is obtained by using a number of laterally expanded ceramic blocks having openings in one side of the top of the block in which plants may be placed. A "living" wall may be formed in this way in which strawberries, tomatoes, and flowers appear to climb up the wall, which is usually a retaining wall, but can also be the wall of a building.
As indicated above, the present inventor has received previous U.S. Pat. No. 4,780,433 issued Oct. 25, 1988 (the parent application of the present inventor's continuation-in-part application which is now U.S. Pat. No. 4,873,207) for an insulated ceramic building material formed of a mixture of cement, a so-called ceramic grog, plus ceramic aggregate beads, the grog and beads being mixtures of clay and a dried organic mulch material, the entire structure being porous after it is fired. The mixture is preferably up to three parts organic mulch material to one part clay, or in other words, 75% organic material and 25% clay material. The organic mixture is formed from burnable trash that, when fired, leaves small orifices in the clay mixture, which can then be mixed with cement to make porous insulating concrete.
The present inventor has found his block of the present invention to be particularly useful when made using his previously disclosed, porous insulating material, or partially of such material. However, his new block can equally well be formed from conventional concrete mixes which form an interlocking block which can be used with similar interlocking blocks to construct a variety of walls for building, as well as retaining walls which are either insulated or uninsulated.
When interlocking blocks are stacked, an inconsistency in the inherent dimensional tolerances between interlocking blocks becomes exaggerated throughout the wall from one interlock to the next, thereby amplifying the inconsistency and reducing the effectiveness of the interlock. The present inventor has recognized that a block with a square cross section, as opposed to a block with an elongated cross section in either the longitudinal or transverse direction, reduces and effectively overcomes inconsistencies brought about by differing tolerances inherent in the construction of the block. However, oblong-shaped blocks with minimal inconsistencies in tolerance would function in an equivalent manner.
There are both parallel vertical and parallel horizontal grooves designed into the sides of the block of the present invention which serve a variety of purposes. These grooves can accommodate supporting or stiffening pieces to reinforce the interlock between the blocks, can add places to incorporate additional insulation, serve as an internal network for electrical or piping conduits, or a combination of all three. The interlocking arrangement of the blocks in combination with the multi-directional grooved system creates a reinforced structure with a unique grid-type transmission system for wiring, cable, plumbing or the like.
The following prior patents disclose prior art concrete blocks developed with respect to interlocking blocks, blocks for retaining walls and insulating blocks and are exemplary of the type of blocks previously available in the art.
U.S. Pat. No. 802,903 issued Oct. 24, 1905 to Z. Anderson discloses an interlocking structure formed from tenon-shaped ribs, such structure requiring four different types (inner and outer side blocks plus inner and outer corner blocks) of blocks to form a complete wall. There are horizontal grooves dimensioned to receive the grasping ends of bonding irons in addition to mortar, and vertical grooves primarily for the insertion of mortar and other permanent bonding agents.
U.S. Pat. No. 1,097,148 issued May 19, 1914 to G. A. Swanson discloses an interlocking building block with interfitting corner blocks.
U.S. Pat. No. 2,683,980 issued Jul. 20, 1954 to W. Krause discloses an insulated building structure formed of a series of insulated blocks having grooves along the top and bottom surfaces with a longitudinal piece, or "lintel", extending between the ceramic or other blocks in the grooves. It is said that the longitudinal lintels, which may be of wood, metal or other materials, not only serve to align the blocks, but also to assist in securing them together.
U.S. Pat. No. 2,884,780 issued May 5, 1959 to T. C. Ramirez discloses a wall of interlocked blocks, each block consisting of a dovetail-shape arrangement on opposites sides of the block. An additional element is specially constructed to interlock at the end of the wall with the standard building blocks and provides for a vertical groove specifically disclosed for the transmission of utility conduits. The block of the present invention incorporates multi-dimensional grooves within its standard construction, unlike the Ramirez groove-bearing block which is distinct from its standard construction and specifically designed to provide the additional aspect of a groove only in a specific location along the wall.
U.S. Pat. No. 3,817,013 issued Jun. 18, 1974 to D. A. Selby discloses an insulated block made in two halves with a layer of insulation between them. The two halves of each block are held together by an interlocking keystone-shaped interconnection between the two halves of each block.
U.S. Pat. No. 4,081,969 issued Apr. 4, 1978 to W. L. Clarke discloses earth retaining wall constructions having leader and stretcher blocks arranged in tiered formation.
U.S. Pat. No. 4,524,551 issued Jun. 25, 1985 to R. Scheiwiller discloses construction units for the erection of walls and method of utilization wherein each unit is engaged to another unit through interlocking, longitudinal slots spanning the width of the units. The wall construction described herein is partially adapted for drywall construction and producing walls with sound proofing quality.
U.S. Pat. No. 4,638,617 issued Jan. 27, 1987 to B. R. James discloses a refractory curtain wall comprised of interlocking, self-supporting members suspended by a hanger member. The James reference does not disclose grooves within the interlocking members.
U.S. Pat. No. 4,815,897 issued Mar. 28, 1989 to A. Risi et al. discloses a retaining wall formed of interengaging blocks and ties, the interengaging parts being formed of rectangular grooves and extensions.
U.S. Pat. No. 4,825,619 issued May 2, 1989 to P. J. Forsberg discloses a block retaining wall comprised of superimposed units arranged in row formation. The blocks disclosed herein can be a plurality of shapes and are generally made of concrete.
U.S. Pat. No. 4,896,999 issued Jan. 30, 1990 to W. Ruckstuhl discloses a set of concrete building blocks for constructing a dry wall. Keystone-shaped projections extend from the base of the block. The patent specification refers to these projections as "dovetail-shaped". The dovetails are spaced along the edge of the blocks mostly along the interior perimeter. FIG. 4 of Ruckstuhl shows a "rectangular recess" described in the specification which transverses the height of the block. As disclosed, therein, the unusual purpose of the recess is to provide shelter for small animals. There are no grooves transversing the length of the block.
U.S. Pat. No. 4,932,812 issued Jun. 12, 1990 to C. F. Schaaf discloses an intermeshable construction unit wherein the units have interlocking teeth that form an interlock between two units. Similar to the above cited patents, no mortar is needed to facilitate the interlocking.
U.S. Pat. No. 5,122,015 issued Jun. 16, 1992 to C. J. Shen et al. discloses a construction assembly for a sea wall formed from a plurality of female and male block members. The female block has a semicircular recess across its length that, when adjacent another female member, forms a circular recess for the purpose of allowing water to pass through the wall. The Shen patent discloses a recess transversing the longitudinal dimension of the block, however, the purpose of the recess is to alleviate pressure from the wall by allowing water to pass through. Blocks are stacked one upon another by use of interlocking protrusions and grooves.
U.S. Pat. No. 5,127,770 issued Jul. 7, 1992 to J. Dichter et al. discloses a retaining wall assembly utilizing face panels interlocked with tieback/anchors. This invention dramatically reduces the overall weight of the assembly by eliminating the need for metallic reinforcing bars which are commonly employed in the prior art as support means.
U.S. Pat. No. 5,163,261 issued Nov. 17, 1992 to R. J. O'Neill discloses a retaining wall structure adapting interengaged support members. The support member has grooves uniformly spaced over its legs which allow for the superimposed structures to be vertically stacked on each other.
U.S. Pat. No. 5,205,097 issued Apr. 27, 1993 to G. L. Harvey discloses an interlocking pier assembly wherein blocks are vertically stacked and interconnected through rectangular recesses and interengaging longitudinal extrusions to support an overlying structure.
U.S. Pat. No. 5,226,275 issued Jul. 13, 1993 to D. H. Trahan discloses an interlocking block assembly for building purposes in which each block is connected to adjacent side blocks by a mortise and tenon arrangement having an expanded keystone interlocking shape, and is secured to upper or lower blocks by having lower external edges fit about a raised central portion of the block below. The composition of the blocks does not appear to be given, but based upon their shape, the thickness of the side walls, and the fact that insulation may be packed in the hollow central region, it may be a plastic resin composition of some form.
U.S. Pat. No. 5,350,256 issued Sep. 27, 1994 to J. Hammer discloses interlocking retaining walls, blocks and system. The drawings indicate the use of a keystone interlocking mechanism to provide structural stability for the wall by tying spaced concrete blocks together with longitudinal members.
There has been a need, therefore, for a well-designed, interlocking block that can be used essentially by itself with a number of other blocks to form a wall for a building or outdoor location, is self-locking, but easily assembled with other blocks, and is easily adapted to insulated construction. There has also been a need for an improved retaining wall block, including so-called "garden wall" blocks, that can be interlocked together to provide a structurally strong arrangement that can resist transverse forces on the side of the block in the case of a retaining wall block, and effectively contain living plants without overheating and instability in the case of garden wall blocks used to construct various walls such as the walls of buildings and the like.